Some session replays are hours of duration (iOS/Android and even web)

[Fernandomr88]

Version

5.15.2

Steps to Reproduce

I have a flutter app that has no background activity going (apart from push notifications) and some sessiona recordings have hundreds of hours of duration, but the user used the app for a few seconds only.

posthog AI says it's reusing the ID and then it considers sessions (sometimes days apart) as the same, so inactive time becomes huge.

Expected Result

I expect the duration to be accurate

Actual Result

but the duration is very imprecise

[marandaneto]

@Fernandomr88 thanks
I find it odd that the same issue occurs across all SDKs, since each SDK manages the session ID.
Can you share your setup? Code snippets of the SDK init, wrapping, etc., do they happen on older versions of the SDK?

[Fernandomr88]

@Fernandomr88 thanks I find it odd that the same issue occurs across all SDKs, since each SDK manages the session ID. Can you share your setup? Code snippets of the SDK init, wrapping, etc., do they happen on older versions of the SDK?
@marandaneto

on flutter:

     final config = PostHogConfig('phc_mP******ekD')
    ..debug = kDebugMode
    ..captureApplicationLifecycleEvents = true
    ..host = 'https://us.i.posthog.com'
    ..sessionReplay = !kDebugMode
    ..sessionReplayConfig.maskAllTexts = false
    ..sessionReplayConfig.maskAllImages = false
    ..errorTrackingConfig.captureFlutterErrors = !kDebugMode
    ..errorTrackingConfig.capturePlatformDispatcherErrors = !kDebugMode
    ..errorTrackingConfig.captureIsolateErrors = !kDebugMode
    ..errorTrackingConfig.captureNativeExceptions =
        !kDebugMode // Android only
    ..errorTrackingConfig.captureSilentFlutterErrors = !kDebugMode;

  config.sessionReplayConfig.throttleDelay = const Duration(milliseconds: 1000);

  await Posthog().setup(config);

on web:

posthog.init(
    'phc_mP******ekD',
    {
        api_host: 'https://us.i.posthog.com',
        person_profiles: 'identified_only',
        capture_pageview: false,
        capture_pageleave: true,
    }
)

[marandaneto]

@Fernandomr88 can you share your wrapping code? where you call Posthog().setup, I also want to see how you set up the PostHogWidget and PosthogObserver, etc.
Does it happen on older versions of the SDK?
The more context, the better.

[Fernandomr88]

@marandaneto

@Fernandomr88 can you share your wrapping code? where you call Posthog().setup, I also want to see how you set up the PostHogWidget and PosthogObserver, etc. Does it happen on older versions of the SDK? The more context, the better.

talking to posthog AI it said that probably the issue is that the sdk is reusing session id. dunno if it helps but the weird thing is that it's happening on mobile and web...

yes it happened on older versions too, its been happening for a while, since posthog_flutter 5.9.0 and for web since 1.256.2 until latest on both.

wrapper and observable:
iOS:

PostHogWidget(
          child: Theme(
            data: ThemeData(
              useMaterial3: false,
              primarySwatch: CustomColors.purpleSwatch,
              primaryColor: CustomColors.purple,
              brightness: Brightness.light,
            ),
            child: GetCupertinoApp(
              title: _title,
              debugShowCheckedModeBanner: false,
              theme: const CupertinoThemeData(
                primaryColor:  CustomColors.purple,
                barBackgroundColor: CustomColors.purple,
                brightness: Brightness.light,
              ),
              initialRoute: '/',
              routes: Routes.getRoutes(context),
              navigatorObservers: <NavigatorObserver>[
                FirebaseAnalyticsObserver(analytics: Requests.analytics),
                PosthogObserver(),
                SentryNavigatorObserver(),
              ],
              navigatorKey: NavigationService.navigatorKey,
              color: CustomColors.purple,
              localizationsDelegates: const [
                GlobalMaterialLocalizations.delegate,
                GlobalCupertinoLocalizations.delegate,
                DefaultWidgetsLocalizations.delegate,
              ],
              supportedLocales: const [Locale('pt', 'BR')],
            ),
          ),
        )

Android:

PostHogWidget(
          child: SafeArea(
            bottom: true,
            child: GetMaterialApp(
              title: _title,
              navigatorKey: NavigationService.navigatorKey,
              debugShowCheckedModeBanner: false,
              navigatorObservers: <NavigatorObserver>[
                FirebaseAnalyticsObserver(analytics: Requests.analytics),
                PosthogObserver(),
                SentryNavigatorObserver(),
              ],
              theme: ThemeData(
                useMaterial3: false,
                primarySwatch: CustomColors.purpleSwatch,
                primaryColor: CustomColors.purple,
                brightness: Brightness.light,
              ),
              initialRoute: '/',
              routes: Routes.getRoutes(context),
              localizationsDelegates: const [
                GlobalMaterialLocalizations.delegate,
                GlobalCupertinoLocalizations.delegate,
                DefaultWidgetsLocalizations.delegate,
              ],
              supportedLocales: const [Locale('pt', 'BR')],
            ),
          ),
        ),

main.dart

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await dotenv.load(fileName: ".env");
  final config = PostHogConfig('ph******kD')
    ..debug = kDebugMode
    ..captureApplicationLifecycleEvents = true
    ..host = 'https://us.i.posthog.com'
    ..sessionReplay = !kDebugMode
    ..sessionReplayConfig.maskAllTexts = false
    ..sessionReplayConfig.maskAllImages = false
    ..errorTrackingConfig.captureFlutterErrors = !kDebugMode
    ..errorTrackingConfig.capturePlatformDispatcherErrors = !kDebugMode
    ..errorTrackingConfig.captureIsolateErrors = !kDebugMode
    ..errorTrackingConfig.captureNativeExceptions =
        !kDebugMode // Android only
    ..errorTrackingConfig.captureSilentFlutterErrors = !kDebugMode;
  config.sessionReplayConfig.throttleDelay = const Duration(milliseconds: 1000);

  await Posthog().setup(config);

  await Firebase.initializeApp(options: DefaultFirebaseOptions.currentPlatform);
  SystemChrome.setPreferredOrientations([DeviceOrientation.portraitUp, DeviceOrientation.portraitDown]);
  await SentryFlutter.init((options) {
    options
      ..attachScreenshot = true
      ..debug = kDebugMode
      ...//other sentry options

  }, appRunner: () => runApp(SentryWidget(child: const App())));

[marandaneto]

@Fernandomr88 ok looks like your setup isnt following the requirements
https://posthog.com/docs/session-replay/installation/flutter
1st check that the AUTO_INIT is disabled for Android and iOS
PostHogWidget has to be the root widget, in your case its SentryWidget and I'm not sure if this is causing any conflicts.
Try moving the PosthogObserver as the 1st item in the navigatorObservers array.

https://posthog.com/docs/data/sessions#how-does-posthog-define-a-session
the session id rotates if the app is either fully closed or is in the background for more than 30 minutes.
If the app is always in the foreground, the session id is never rotated, unless it exceeds 24 hours.

if none of this helps, please provide a MRE since i've tested this locally and everything seems to be working fine, sessions id are rotated normally in our sample apps

[Fernandomr88]

@Fernandomr88 ok looks like your setup isnt following the requirements posthog.com/docs/session-replay/installation/flutter 1st check that the AUTO_INIT is disabled for Android and iOS PostHogWidget has to be the root widget, in your case its SentryWidget and I'm not sure if this is causing any conflicts. Try moving the PosthogObserver as the 1st item in the navigatorObservers array.

posthog.com/docs/data/sessions#how-does-posthog-define-a-session the session id rotates if the app is either fully closed or is in the background for more than 30 minutes. If the app is always in the foreground, the session id is never rotated, unless it exceeds 24 hours.

if none of this helps, please provide a MRE since i've tested this locally and everything seems to be working fine, sessions id are rotated normally in our sample apps

Made those changes, let's see if the problem persists.

Any idea on why would it happen on web too?

[marandaneto]

Any idea on why would it happen on web too?

No, because we don't even sync the session id to the web.
Let us know if that helps, or provide an MRE.